7005095: Cast: compile reject sensible cast from final class to interface

Summary: a previous fix to cast conversion has made the compiler too strict w.r.t. final cast
Reviewed-by: jjg

src/share/classes/com/sun/tools/javac/code/Types.java

@@ -1033,12 +1033,7 @@ public class Types {
                                 && !disjointTypes(aHigh.allparams(), lowSub.allparams())
                                 && !disjointTypes(aLow.allparams(), highSub.allparams())
                                 && !disjointTypes(aLow.allparams(), lowSub.allparams())) {
-                                if (s.isInterface() &&
-                                        !t.isInterface() &&
-                                        t.isFinal() &&
-                                        !isSubtype(t, s)) {
-                                    return false;
-                                } else if (upcast ? giveWarning(a, b) :
+                                if (upcast ? giveWarning(a, b) :
                                     giveWarning(b, a))
                                     warnStack.head.warnUnchecked();
                                 return true;
@@ -3377,8 +3372,8 @@ public class Types {
         public Type visitCapturedType(CapturedType t, Void s) {
             Type bound = visitWildcardType(t.wildcard, null);
             return (bound.contains(t)) ?
-                    (high ? syms.objectType : syms.botType) :
-                        bound;
+                    erasure(bound) :
+                    bound;
         }
 
         @Override
@@ -3386,7 +3381,7 @@ public class Types {
             if (rewriteTypeVars) {
                 Type bound = high ?
                     (t.bound.contains(t) ?
-                        syms.objectType :
+                        erasure(t.bound) :
                         visit(t.bound)) :
                     syms.botType;
                 return rewriteAsWildcardType(bound, t);

test/tools/javac/cast/7005095/T7005095neg.java

+/*
+ * @test /nodynamiccopyright/
+ * @bug     7005095
+ * @summary Cast: compile reject sensible cast from final class to interface
+ * @compile/fail/ref=T7005095neg.out -XDrawDiagnostics T7005095neg.java
+ */
+
+class T7005095pos<T extends Integer> {
+    interface Foo<T> {}
+
+    static final class FooImpl implements Foo<String> {}
+
+    Object o = (Foo<T>) new FooImpl();
+}

test/tools/javac/cast/7005095/T7005095neg.out

+T7005095neg.java:13:25: compiler.err.prob.found.req: (compiler.misc.inconvertible.types), T7005095pos.FooImpl, T7005095pos.Foo<T>
+1 error

test/tools/javac/cast/7005095/T7005095pos.java

+/*
+ * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug     7005095
+ * @summary Cast: compile reject sensible cast from final class to interface
+ * @compile T7005095pos.java
+ */
+
+class T7005095pos<T extends CharSequence> {
+    interface Foo<T> {}
+
+    static final class FooImpl implements Foo<String> {}
+
+    Object o = (Foo<T>) new FooImpl();
+}